Electrical condenser for high tension circuits



June 6, 1939. J. K. WEBB 2,161,326

ELECTRTCAL CONDENSER FOR HIGH TENSION CIRCUITS Filed Oct. 30, 1936 2 Sheets-Sheet l IHVEHTOK J. KWEBB ATTORNEY June 6, 1939. 1. K. WEBB 2, 6

' ELECTRICAL CONDENSER FOR HIGH TENSION CIRC UITS v Filed 001:. so, 1936 2 Sheets-Sheet '2 I I 0 l v BY ATTORNEY i Patented June 6, 1939 UNITED STATES PATENT OFFICE ELECTRICAL CONDENSER FOR HIGH TIN- SION CIRCUITS ternational Stan New York, N. Y.

dard

Electric Corporation,

Application October 30, 1938, Serial No. 108,446

InGrcatBrltain scum.

Thisinvention relates to electrical condensers for high tension current, and has for its object to provide a compact construction of condenser having a large capacity and particularly suitable 5 for, use in connection with power line carrier systems where it is required to tap oil high frequency currents from a high voltage line and/or for terminating such lines. In such cases the such a high capacity as 250 mmf. would have an inconveniently long outer metal foil, which would lead to weakness as far as extended fiashover was concerned. Such an arrangement would be impractical and uneconomical.

25 The difiiculty is overcome according to the present invention *by which a plurality of cones are connected in parallel by providing cones of different diameters and arranging them to fit one within the other concentrically. Each cone will to the increased diameter of the outer cone, the length of its outer metal foil will'be reasonably short. Thus a long outer graded surface is provided which will considerably reduce the risk a of external fiashover.

The cones may be arranged alternately with the base of one engaging the apex of another, thereby ec'onomising in space and at the same time giving the necessary cone-to-cone contacts for the parallel connection.

The invention will be better understood by reference to the accompanying drawings in which: i

Fig. l isa diagrammatic representation of the condenser cones arranged according to this invention;

Fig. 2 is a sectional view of a condenser construction according to the invention, suitable for power line carrier systems.

Referring to Fig. 1, it will be seen that the condenser comprises four cones indicated respectively as I, 2, 3 and 0. Cone i is mounted at its apex end on a central iormeror tube 5. The apex end of cone 2 fits over the base oi cone l and similarly the apex end of cone 3 have approximately the same capacity, and due November 15, 1935 of cone 4 fits over the base of cone 3. In the drawing the lines 6 represent the conductive layers or metal foil cylinders of the condenser which are separated by suitable insulating material indicated at lfisuch asiayers of paper. The conductive layers at the junctions between adjacent cones indicated at 6' may comprise two foils in contact, that is, the inner foil of one, cone and the outer foil of another cone, or one common foil may be provided. The terminals of the condensers are connected to the layers 8 at opposite ends, as indicated by the connections 8 and I respectively.

Turning now to Fig. 2, it will be seen that the condenser cone arrangement diagrammatically represented in Fig. 1 is housed in a sealing chamber ll which may be of porcelain, and is similar to the sealing end constructions used for high tension cable terminals, being provided with a metal cap II, to which electrical connection is made at one end. The base of the chamber is provided with a metal cap II, to which a terminal II is secured, and inside this can is provided a metal platform It on which the condenser cones stand, and which provides a common terfits over the base of cone Land the apex end minal for one end thereof, being connected to the C terminal device I! passing through insulating bushes l6 in'the metal cap ii. The platform It .is separated from the cap I 2' by insulating bushes ll located on insulating pins ll' screwed into the metal ca At the upper end of the chamber the cap Ii is electrically connected to the condenserby the flexible connection II and suitable filling plugs I! may beprovided. The arrangement of condenser shown in Fig. 2 would be used for taking a high frequency tapping from an overhead line, the connection to the line being made to the cap 'II and the high frequency connection being made to the terminal It. The terminal It would be connected to earth through a spark gap or other suitable safety device to deal with surges or incipient breakdowns.

The chamber ll would be filled with a suitable insulating compound and if desired, the central space may be utilised to house pressure c'ompensators for dealing with thermal expansion and contraction of the compound. The compound may thus be kept, if desired, under pressure, thereby ensuring an increase of the electrical breakdown value.

In order to increase the resistance to high voltage breakdown, or to increase the electrostatic capacity of the system, the condenser cones may be impregnated with a high permittivity material and the filling compound may also be of high permittivity. The filling compound which may be liquid or semi-solid, or in some cases solid, may alternatively be raised in dielectric loss value to assist in radial stress grading as described in the British application No. 2/35. An example is the styrene alcohol mixture mentioned in this case.

It will be understood that the arrangement of parallel connected cones in accordance with this invention may be used for a cable terminal with or without means for tapping oif high frequency currents, and may be employed in a normal sealing chamber used for such cable terminals. Moreover, the condenser cones may be embedded in a solid insulating material such as styrene, as described in the above-mentioned British application 2/35 and in such form' may in some cases be used without the protection of a sealing chamher. The cones may be constructed with metal foil and paper which may be impregnated with suitable insulating compounds, such as oil or styrene, and the complete series of parallel connected cones may be constructed as one unit or they may be built up of separate cones, which are afterwards fitted one within the other as described.

It will be seen that the present invention provides a simple and compact construction of condenser which may be made of large capacity, occupying a small space and suitable for very high tension currents.

What is claimed is:

1. An electrical condenser comprising a plurality of parallel connected conical condenser elements concentrically disposed all at substantially the same position axially and successively one within the other, each of said elements comprising a number of coaxial insulation-separated cylindrical conductive layers of different diameters, the conical elements being arranged with the apices of alternate elements at opposite ends of the condenser and with the base of one engaging the apex of another.

2. An electrical condenser according to claim 1, wherein the terminal connections of the condenser are taken from opposite ends of the cones and from the condenser plates between adjacent cones.

3. An electrical condenser according to claim 1, further comprising a ceramic chamber having metallic end portions, a metal platform mounted within said chamber adjacent one of said end portions but insulated therefrom, a terminal external to said chamber connected to said platform, a second terminal external to said chamber connected to said one of said end portions, the concentrically disposed conical condenser elements being supported within said chamber from said metal platform, terminal connections from certain of said conductive layers to said platform, and a third terminal external to said chamber and connected to others of said conductive layers.

JOHN KRAUSS WEBB. 

